Generally, when you are receiving unwanted parenting advice it is best to just acknowledge that you heard what they are saying, take it with a grain of salt and try to change the conversation. However, there are people that are just giving you a random comment and others that may really step over the line. If the frequency as to which the comments are made is bothering you then it needs to be addressed. Take the person aside and let then know that their comments are intruding on your parental choices and you wish for them to refrain from negativity when speaking to one another. This way you will have stated that you are uncomfortable with the remarks in a non-confrontational manner and they may not get defensive. If they are offended, then that is their reaction but you will have told them how you feel about it. Some people are unaware that their comments are hurtful and they should know that it made you feel uncomfortable.
If the comments are being made in front of the child, that type of behavior needs to stop immediately. It is confusing to the child and directly undermines the parent. If this type of interaction is occurring, your first step is to ask the child to leave the room. You do not know what might come out of the person’s mouth next and an adult conversation needs to be had about the matter. Take time to calm down and let them know that type of behavior is unacceptable, especially in front of the children. Explain to them that your children are familiar with your parental choices and they should not be included in conversations that are disrespectful to you as a parent. After the incident, the child needs to understand that you, as the parent have made decisions about your family and although other people may disagree with your choices it is not okay for them to express their opinions in front of the children.